1. Field of the Invention
This invention relates to novel, crosslinked polyalkylenepolyamines and a process for their preparation.
2. Description of the Prior Art
Linear, acylated polyalkylenepolyamines are known to absorb large amounts of water and to interact with various colorants present in bleach Kraft-pulp effluents. However, these polymers are water-soluble and as such not readily adaptable to the aforementioned utilities. The only present art-recognized method for rendering these polymers water-insoluble is to graft same onto various resin beads ("Oxazoline and/or Oxazine-Modified Polymers" by Chamberlin et al., Ser. No. 639,152 and filed Dec. 9, 1975). This method is generally efficient for polymers having a relatively small number of repeating units, e.g., less than about 15, but is generally inefficient for polymers having a relatively large number of repeating units, e.g., more than about 20. Moreover, a larger ratio of amide to polymer weight or volume than that afforded by the grafted polymers is desirable for reasons of nitrogen functionality.
Weiner, J. Org. Chem., 25, 2245 (1960) teaches the preparation of N,N-dimethyl-N'-phenylformamidine from the reaction of phenyl isocyanate and N,N-dimethyl-formamide. The teaching is silent as regards polymeric and polyisocyanate reactants.